Editor's Note: This is Part Two in a series of safety articles by Mark Yager. A long-time motorcycle enthusiast, Mark is currently an instructor at the Canada Safety Council.
Steering a motorcycle is fairly straightforward, right? It may seem that way, but as you turn for a corner there are a lot more things happening than you probably realize. Being able to turn your bike aggressively and avoid running into that car that just pulled out in front of you largely depends on what you know about these mysterious forces. Read on....
Physics 101
Above a speed of about 20 to 30 km/h (15-20 mph), the motorcycle's wheels act like gyroscopes. These spinning masses of wheel and tire combine to create a gyroscopic force -- if you've ever held a spinning bicycle wheel in your hand and felt how difficult it is to "steer" it, you'll understand. So how do we overcome this force to get our bike to turn?
We don't.
Use the Force...
If you've ever played with a gyroscope, you'll remember that pushing forward on the left end of the axle didn't result in the wheel turning to the right. Instead, thanks to a force called gyroscopic precession which redirects the force 90 degrees in the direction of rotation, the wheel actually leaned to the left, rotating on an axis around the center of the wheel. Your motorcycle works the same way. By turning the handlebars to the right, you are effectively inputting the same force we used in our example. Trying to push the spinning wheel to the right causes the wheel, and the rest of the bike attached to it, to lean to the left. This is called counter-steering. Turn the bars right, and you lean left. It is the only way a motorcycle steers at any speed above walking speeds. Those of you saying "No way, dude, I never do it that way," are wrong. And this is why so many motorcyclists actually steer into and accident -- they try and turn right to avoid an incident by turning the front wheel to point to the right. This, in turn, steers them left, straight into the accident. So whether you realize it or not, you are doing "it," better known as counter-steering.
When the bike is at a desired lean angle, ease up on the bars, and the bike will remain there assuming the tire profiles aren't working against the bike and trying to stand it up. If you let up on the throttle, the bike will turn in, and conversely, adding throttle will make the bike run wider. To straighten the bike back up, add a smooth combination of throttle and reverse steering input. If you are in a left hand turn, turn the bars farther to the left, and the bike will stand up.
Some people ask how hard to push. Please understand that this is not a sharp jab at the bar. It is a smooth, steady pressure with the key word being smooth. The higher the speed at which the bike is traveling, the more gyroscopic effect there is, therefore you will need to push harder. This is why road racers work on upper body strength so much.
Why Counter-Steering?
Again, we cannot stress this point enough: Imagine yourself cruising down the highway on a beautiful spring day. Suddenly you see (insert your worst nightmare here) in the road, covering the right two-thirds of your lane. If you do not consciously understand and use counter-steering, you will probably push on the right bar in an attempt to steer left like you would on a slow moving bicycle or in a car where you steer left to go left. Pushing on the right will steer you directly into the object. The correct action here would be to push on the left bar and steer away from the obstacle. So remember: "Push left, turn left. Push right, turn right." Repeat this to yourself over and over while you ride. Once you get the hang of it, counter-steering will become instinctive -- your body probably knows how to do it, it's just your mind that is lagging. Understanding the principles behind counter-steering will make you smoother and give you a better feeling of control over your environment. It may also save your life. Like any safety technique, it only works if you practice it. Unless the action is second nature, you will return to your old habits during an emergency. So, practice, practice, practice.